If firefox had a setting, maybe per-site, to prevent text boxes from "helpful" editing key overrides it would be wonderful.

I have to use a web application that uses CKEditor for text boxes.

And just like you - the most annoying thing in the world - j I get: control-b is bold instead of back one character (one of my most commonly used keystrokes)

The other annoying one is control-k pops up a link dialog.

I tried to figure out how to override or disable it, but never got very far.